1. Field
One or more exemplary embodiments relate to a device and method of controlling a disk cache, wherein time of seeking a disk cache may be shortened and a hit rate of a disk cache may be increased.
2. Description of the Related Art
In general, hard disks have a large capacity but they have a low access speed. Thus, as access to a hard disk increases, an input/output (I/O) time may increase and a speed of processing data may decrease. Accordingly, disk cache technology is widely used to reduce access to a hard disk.
Recently, data that is read out from a hard disk may be stored in a buffer cache of a main memory. Thus, when a central processing unit refers to the data afterwards, the data may be read out from the buffer cache without accessing the hard disk. Accordingly, when the disk cache technology is used, access to a hard disk may be reduced, and therefore the speed of processing data may increase.
As technologies related to storage devices are developed, storage devices including flash memories are being widely distributed recently. For example, solid state disks (SSDs) include high-speed semiconductor memories such as Not AND (NAND) flash memories or dynamic random access memories (DRAMs). Unlike hard disks, SSDs enable random access, and therefore data may be accessed within a short seeking time.
Accordingly, storage devices including flash memories may have a higher access speed than hard disks. Although storage devices including flash memories have a lower data access speed than main memories, in general, storage devices including flash memories may have a larger capacity than main memories.
Storage devices including flash memories may be used as disk caches. In other words, data that is read out from a hard disk may be stored in a flash cache of a storage device including a flash memory.